Porous granular material obtained from wool scouring liquor, method for the manufacture thereof and applications

ABSTRACT

The porous granular material according to the invention comprises carbon, silica, water-soluble mineral salts and water-insoluble mineral salts, does not disintegrate in the presence of water and has a particle size of approximately 1 to 5 mm, preferably from 1 to 3 mm, in particular from 1 to 2 mm; a crushing strength, or mechanical strength, in the range of 0.75 to 1 MPa; a density of between 0.7 and 0.8; a BET specific surface area of between 100 and 200 m 2  /g; a microporous volume of between 0.25 and 1 cm 3  /g; and a carbon content of 8 to 11 weight %, the balance being essentially made up by a mineral matrix of base nature, comprising a crystalline phase of insoluble aluminosilicates. 
     Application, in particular, to the purification of liquids, as a catalyst in oxidation reactions and in the manufacture of composite catalysts, in particular in petrochemistry.

The invention relates to the valorization of the residues obtained afterde-polluting wool scouring water or liquor.

It relates more especially to a porous, granular material that can beused, in particular, as an absorbent product and as a catalyst support,for example in petrochemistry, in particular for sweetening gasolines.

The invention also relates to a process for the manufacture of thisporous, granular material and to the applications of this material.

Raw wool obtained after sheep shearing contains foreign materials suchas wool grease (a mixture of esters of alcohols and fatty acids,insoluble in water), suint (a mixture of water soluble organic potassiumsalts) earth, sand, etc. This wool is washed with water to remove theseimpurities therefrom. After evaporation of the washing or scouringwater, a greasy, earthy mass is obtained.

The Applicant initially had the idea of valorizing wool scouring watersby concentrating them to approximately 70% dry matter by evaporation andthermocompression, and then pyrolyzing, at betweeen 400° and 600° C.,the sludge thus obtained in a rotary furnace, with hot gas counter-flow.He thus obtained, on one hand, essentially a mineral material in theform of ashes composed of approximately 70% of granulates andapproximately 30% of fine dusts and, on the other hand, by passing thepyrolysis gases through a boiler, high pressure steam used to produceelectricity.

The mineral material in question, which is essentially composed ofcarbon, water-soluble potassium salts, water-insoluble potassium salts,silicates and silica, is used, in powder form (granulates and finedusts) in agriculture, as a fertilizer.

The granulates are also used as catalyst supports, in particular tosweeten gasolines, or directly to deodorize or bleach liquids.

It has been established, however, that the porous, granular materialobtained from this first pyrolysis exhibited a highly irregularperformance and, in certain applications, had drawbacks such asinsufficient crushing strength and a tendency to disintegrate in thepresence of water.

The Applicant thus continued his research with a view to improving thisgranular material. In this way, he found that, thanks to a secondpyrolysis, carried out at temperatures of 700° to 950° C., in particularfrom 700° to 800° C., and preferably from 700° to 750° C. in anon-oxidizing atmosphere, it was possible to obtain, reproducibly, aporous, granular material that not only exhibited very good crushingstrength and did not disintegrate in the presence of water, but also hada far larger specific surface area than the granulates from the firstpyrolysis, with microporosity predominating, to the detriment ofmacroporosity. These new granulates, which can be obtained either bygrinding, compacting and granulation, followed by a second pyrolysis, ofthe mineral material obtained after the first pyrolysis, or by a second,direct pyrolysis of granulates from the first pyrolysis having aparticle size ranging from approximately 1 to 5 mm, are capable, inaddition, of fixing, by absorption or adsorption, far larger quantitiesof products such as catalysts.

More precisely, according to one of its aspects, the invention relatesto a porous, granular material comprising carbon, silica, water-solublemineral salts and water-insoluble mineral salts, characterized in thatit does not disintegrate in the presence of water and has:

a particle size in the range of approximately 1 to 5 mm;

a crushing strength, or mechanical strength, in the range of 0.75 to 1MPa;

a density of between 0.7 and 0.8 g/cm³ ;

a BET specific surface area of between 100 and 200 m² /g;

a microporous volume of between 0.25 and 1 cm³ /g; and

a carbon content of 8 to 11 weight %, the balance being essentially madeup by a mineral matrix of base nature, comprising a crystalline phase ofinsoluble aluminosilicates.

In the framework of the present invention, the microporosity is taken asbeing constituted of pores less than or equal to 18×10⁻¹⁰ m (18 Å),while the macroporosity is taken as being constituted of pores largerthan or equal to 200×10⁻¹⁰ m (200 Å).

The porous, granular material according to the invention has a particlesize at least equal to approximately 1 mm. In the course of itsmanufacture, that will be described later, if one were to attempt towork with a particle size of less than approximately 1 mm, sludge wouldbe obtained, and not a granular material. The particle size preferablyranges from 1 to 3 mm and, advantageously, from 1 to 2 mm. In all cases,this granular material essentially contains the following elements:carbon, silicium, oxygen, sodium, potassium, magnesium, calcium,aluminum and iron. It has a high silica content, generally in the orderof 45 weight %.

It is composed of a high proportion of black grains, which includecarbon, silica essentially in the form of quartz, silicates such asmagnesium and potassium silicate having the formula K₂ MgSi₃ O₈ andaluminosilicates of the alkaline feldspar type such as sodiumaluminosilicate having the formula NaAlSi₃ O₈ and gismondine orpotassium aluminosilicate having the formula KAlSi₃ O₈ or of thefeldspathoid type, less rich in silica than the feldspars, such askaliophilite having the formula KAlSiO₄, or kalsilite having a not verydifferent formula. This porous, granular material further compriseswhite grains, essentially composed of silica, primarily in the form ofquartz.

The presence of aluminosilicates in the porous, granular materialaccording to the invention would appear to be due to a more or lessordered rearrangement of the alkaline cations with the silicon andaluminum ions present in the starting material, a rearrangement whichpartly transforms the soluble silicates into insoluble aluminosilicates.

The granulates obtained according to the prior art already contain acertain proportion of aluminosilicates, in particular gismondine andkaliophilite. The second pyrolysis, which leads to the production of theporous, granular material according to the present invention, modifiesthe proportions of these aluminosilicates and favorably increases thebasicity of the granular material according to the invention, inrelation to the known granular material obtained from the firstpyrolysis. In addition, the larger proportion of feldspathoid materialsuch as kaliophilite increases the crystallinity of the product, thusenhancing its crushing strength.

For certain applications, in particular when it is used as it is, or asa catalyst support in base catalysis applications, for example for thepurpose of sweetening acid petroleum cuts, the porous, granular materialaccording to the invention preferably has a pH value, measured for thewashing waters, of over 11.

The crushing strength, or mechanical strength, is more generally between0.75 and 0.95 MPa.

The BET specific surface area is advantageously between 160 and 200 m²/g.

According to one advantageous form of embodiment, the invention providesa porous, granular material comprising carbon, silica, water solublemineral salts and water-insoluble mineral salts, characterized in thatit does not disintegrate in water and has:

a particle size ranging from 1 to 3 mm, preferably from 1 to 2 mm;

a crushing strength, or mechanical strength, of between 0.75 and 0.95MPa;

a density of between 0.7 and 0.8 g/cm³ ;

a BET specific surface area of between 160 and 200 m² /g;

a microporous volume of between 0.25 and 1 cm³ /g;

a carbon content of 8 to 11 weight %, the balance being essentiallycomposed of a mineral matrix of base nature, comprising a crystallinephase of insoluble aluminosilicates; and

a pH value, measured for the washing waters, of over 11.

According to another of its aspects, the invention provides a processfor the manufacture of the porous, granular material according to theinvention, characterized in that it essentially comprises the steps of:

1. obtaining an essentially mineral material, having, or having not, aparticle size ranging from approximately 1 to 5 mm, preferably from 1 to3 mm, and, advantageously, from 1 to 2 mm, obtained by concentratingwool scouring waters to obtain a dry matter content of approximately70%, pyrolysis of the resulting concentrate at a temperature of between400° and 600° C., with protection from air and cooling;

2. subjecting this material, if necessary, to grinding compacting,granulating and screening operations to obtain a granulate having aparticle size ranging from approximately 1 to 5 mm, preferably from 1 to3 mm and, advantageously, from 1 to 2 mm;

3. subjecting the essentially mineral starting material with a particlesize ranging from approximately 1 to 5 mm, preferably from 1 to 3 mmand, advantageously, from 1 to 2 mm, or the granulate obtained in step2, to a second pyrolysis, in a non-oxidizing atmosphere, at atemperature which is gradually increased from a value ranging from 250°to 350° C. to a value ranging from 700° to 950° C., for a total durationof 15 to 60 minutes; and

4. cooling the granulate thus obtained, with protection from air, andunder conditions such that it is not subjected to thermal shock.

The expression "essentially mineral material" is to be taken here asmeaning a material in a dispersed form which, according to the grainsize of the particles of which it is composed, consists of a granulate,a powder or a mixture of granulate and powder. This material,manufactured by the Applicant, is, as indicated hereabove, already used,in particular, as a fertilizer. The essential steps in its manufactureare represented in diagram form in the SPRINT RA089 document of May1992, entitled "Gestion de l'eau et traitement des effluents dansl'industrie de lavage de la laine brute" (Water management andprocessing of effluents in the raw wool scouring industry). Additionaldetails regarding a method of obtaining the "essentially mineralmaterial" used according to the invention are given hereinafter.

Wool scouring water that contains wool grease, suint, earth and sand issubjected to primary evaporation in several steps, which brings its drymatter concentration to approximately 50 weight %. For this purpose, usecan be made of evaporators composed of a bundle of tubes through whichflows the liquor to be evaporated and of a separator in which the liquoris separated from the evaporation vapors which contain, in addition towater vapor, volatile products such as ammonia, amines and fattyalcohols.

The bundle of tubes is heated on the outside with steam or re-compressedvapors which, upon condensing, transmit their latent vaporization heatto the liquor to be evaporated, which falls in the form of a thin filminside the tubes.

The concentrate thus obtained is then subjected to a secondaryevaporation in forced circulation evaporators whose tube bundles itfills. The concentrate or liquor is heated all along the tubes andevaporation takes place by expansion at the outlet from the bundle oftubes. Following this secondary evaporation, a sludge is obtained whichhas a dry matter concentration of approximately 70 weight %.

For the purpose of carrying out evaporation, use is made of the delay inboiling, which is defined as being the difference between the boilingpoint of a liquid and the boiling point of water under the sameconditions. The delay in boiling is determined by the concentration ofsoluble mineral and organic materials in the boiling liquid. It ismeasured, in practice, by taking the temperature difference existingbetween the boiling liquid and the water vapor that tops it. As aresult, it enables the operator to estimate the dry materials content ofthe concentrate obtained.

The concentrate obtained following the secondary evaporation step iscomposed of:

organic materials (suint and "suintine"): approximately 25%;

water: approximately 30 to 35%; and

mineral materials, earths, potassium hydroxide, sodium hydroxide, etc.:balance to make up 100%.

This concentrate is sent to a pyrolyzer which can be composed of arotary furnace, a multi-level furnace of the NICHOLS-HERRESHOFF type ora furnace with rotary soles of the NICHOLS type. Pyrolysis is carriedout therein at temperatures of between 400° and 600° C. It enables theconcentrate to be transformed by evaporation of the water and of thelight organic materials, thermal cracking of the heavy organicmaterials, softening of the low melting point mineral salts, coating ofthe melted salts with the earths and granulation of the mineralmaterial. The requisite temperatures are maintained in the furnace bycounter-flow circulation of the gases emanating from a hot gas generator(using, for example, natural gas) and the recycled pyrolysis gases. Theessentially mineral material leaving the pyrolizer is then cooled down,for example in a tubular rotary cooler, swept by a counter-flow of coldair inside and of water outside, and then recovered.

The essentially mineral material that can be obtained after this firstpyrolysis, and which is used in the implementation of the processaccording to the invention, contains carbon, suint, water-soluble salts,in particular potassium ones, water-insoluble salts, in particularpotassium ones, silicates and silica. It is generally composed of grainswith a very "open" particle size distribution, that is to say covering awide range of approximately 30 μm to 40 mm.

When one has a material with such an "open" particle size distribution,before subjecting it to the second pyrolysis in step 3 according to theinvention, it is necessary to process it to give it the requisiteparticle size.

For this purpose, the material is ground in such a way that all thegrains have a size of less than 1 mm, and then it is subjected to acompacting treatment to transform it into high density plaquettes, whichare then transformed into a granulate having the required dimensions,namely a particle size ranging from 1 to 5 mm, preferably from 1 to 3 mmand, advantageously, from 1 to 2 mm.

In order to improve the porosity of the final product, that is to thesay the porous, granular material according to the invention, one can,at the time of compacting, add, for example petroleum pitch or coal tarpitch, in a proportion of 5 to 10 weight %, in relation to the weight ofthe powder obtained following grinding.

In addition, in order to modify the characteristics of the finalproduct, such as its ability to provide places favoring catalysiseffects brought into play in certain reactions taking place in oil orchemical industry processes, sludges containing metals such as iron,copper, titanium, vanadium and nickel, or salts of such metals, can alsobe added, at the time of compacting, in the form of a powder having asuitable particle size.

The treatments, if any, carried out in step 2, make it possible not onlyto obtain a granulate having the requisite particle size, but also tointroduce additives designed to modify the characteristics of the finalproduct.

When one has a raw material obtained from the first pyrolysis composedsolely of a granulate with a particle size at least equal toapproximately 1 mm, it is not necessary to subject it to the grinding,compacting and granulation treatments outlined hereabove. It can besubjected directly, after screening, if necessary, in order to obtaingrains having the requisite size, to the second pyrolysis in step 3.

The granulate of the requisite size, resulting or not resulting from thetreatments of step 2, is then subjected to pyrolysis, in a non-oxidizingatmosphere, at a temperature that is gradually increased from a valueranging from 250° to 350° C. to a value ranging from 700° to 950° C. fora total duration of 15 to 60 minutes, in a furnace. This furnace can bea furnace of the same type as that used for pyrolizing the concentrateof the wool scouring waters, but capable of withstanding highertemperatures. Use is preferably made, however, of a rotary furnacehaving refractory walls.

In a rotary furnace, the total pyrolysis time is generally from 15 to 30minutes.

It is also possible, however, to use a static furnace. The totalpyrolysis time is then generally from 40 to 60 minutes.

The temperatures at the furnace input are between 250° and 350° C.approximately, and the furnace output temperatures are between 700° and950° C. approximately.

These temperatures are maintained in the furnace by the counter-flowcirculation of hot gases, for example natural gas, obtained from a gasgenerator fed by a burner.

The atmosphere in the furnace must be non-oxidizing and is preferably areducing atmosphere.

To provide a reducing atmosphere, the recycled gases from the pyrolysisstep can advantageously be mixed, in the gas generator, with the gasessupplied by the burner.

The pyrolized granulate is then cooled down, in the absence of air andunder conditions such that it is not subjected to thermal shock, forexample in fine sand, from which it is then separated by screening or,better still, in a double jacketed tube through which cold water(approximately 15° to 20° C.) is circulated, for example through a"water screw".

In order to obtain the porous, granular material corresponding to theadvantageous form of embodiment of the invention described earlier, thepyrolysis temperature must not exceed 750° C.

Consequently, according to a preferred form of embodiment, the processaccording to the invention defined hereabove is characterized in thatthe second pyrolysis is conducted at a temperature which is graduallyincreased from a value ranging from 250° to 350° C. to a value rangingfrom 700° to 750° C.

The porous, granular material according to the invention can, by reasonof its advantageous physico-chemical characteristics, such as, inparticular, high crushing strength, high specific surface area andabsence of disintegration in water, be used in numerous and variedapplications in which use is normally made of activated charcoal, oftenwith lower efficiency and/or under more complex conditions.

In fact, this material behaves like an absorber, has the strength of analuminosilicate and exhibits a chemical reactivity of the base type.

It can be used as it is or after washing with water for the purpose ofextracting the water-soluble salts therefrom, for example to purify, inparticular, to deodorize liquids containing phenolic residues. It canthus be used, for example, to deodorize the condensates of wool scouringwaters or the condensates of stripping by steam distillation ofpetroleum products.

It can also be used as it is as a catalyst in certain oxidationreactions of major industrial importance, such as the oxidizing couplingof methane, which is a reaction designed to transform this hydrocarbon,in the presence of oxygen, into higher hydrocarbons, in particular withtwo carbon atoms. The use of the porous, granular material according tothe invention in this reaction leads to the production of ethylene (C₂H₄) and ethane (C₂ H₆) with a very favorable ethylene-ethane ratio bycomparison with the other catalysts normally used in this reaction.

It can further be used as it is as a catalyst support. In this case, itis impregnated, according to the usual techniques well known to the manof the art, with the chosen catalyst, which can, for example, be acobalt salt, to remove the sulfur-containing organic compounds givingrise to unpleasant odors, contained, in particular, in water, or aphthalocyanine, such as cobalt phthalocyanine, to neutralize the freefatty acids, for example in the wool grease or suintine, to bleach itprior to its valorization treatment.

The porous, granular material according to the invention can also beused as a catalyst support in different applications in thepetrochemical field, after washing with water to extract the solublemineral salts therefrom.

Thus, this material, after washing with water, can be impregnated with ametallic chelate, for example a phthalocynanine, in proportions of from1 to 5 kg/m³, to form a composite that can be used in the sweetening ofpetroleum cuts. The speed of passage of the petroleum cuts to besweetened is considerably increased in relation to the composites of theprior art, in particular in relation to those obtained with the granularstarting material (the granular material of the first pyrolysis), whichcorresponds to a major productivity increase (see Example 8 in the"experimental section" that follows).

It can further be subjected to a "purification" treatment other thanwashing with water, designed to permit its use in applications otherthan those mentioned above.

Thus, it may be advantageous to remove, at least partially, the carbonthat it contains in order to obtain an even more mineral material, forexample by calcining at temperatures of over 320° C.

Examples of applications of the porous, granular material according tothe present invention are given by way of illustration in theexperimental section that follows.

The figures in the appended drawings represent:

FIG. 1: the flow sheet for a unit for manufacturing the porous, granularmaterial according to the invention from the known product of the firstpyrolysis of the wool scouring waters, using a pyrolizer of the rotaryfurnace type.

FIG. 2: a vertical sectional view of the furnace used in thismanufacturing unit.

These figures will be described in the experimental section thatfollows, in connection with an example of a form of embodiment of theprocess according to the invention.

EXPERIMENTAL SECTION Example 1

Manufacture of the porous, granular material according to the invention

The starting material obtained from the first pyrolysis of the woolscouring waters and the manufacture of which has already been described,was brought, by grinding, to a particle size of less than 1 mm. It canbe mixed at this stage with recycled fine particles, obtained by cyclonefiltration of the gases from the first pyrolysis. The mixture was thensent to a unit composed of a preparation unit for the weighing of thecomponents (previous mixture and fine particles of less than 1 mm,recycled after granulation) and of a unit for compacting, whichtransforms the powdery materials into high density plaquettes. Theparticles were agglomerated by the pressure applied by a hydraulicsystem to the molding wheels of the compactor. In this example, thewidth of a molding wheel was 14.5 cm and the pressure applied was in theorder of 7.10⁴ to 8.10⁴ N (7 to 8 tons) per cm of wheel width.

Correct dimensioning of the compactor, in particular of its wheels,enables 100% compacting efficiency to be obtained.

The high density plaquettes were then transformed, in a granulationunit, into a granulate having the requisite dimensions, namely from 1 to2 mm in the present case. The granulation yield was in the order of 30%.For a particle size of 1 to 3 mm, it would be in the order of 50%.

After screening, the granulate of over 2 mm was recycled to thegranulator and the fine particles of less than 1 mm were recycled to thecompacting unit.

The 1 to 2 mm sized granulate 1 was distributed on a conveyor belt 2 atthe rate of 100 kg/hr and then loaded into a hopper 3, the base of whichwas equipped with an alveolate lock or rotatory sluice 4. They were thusregularly loaded, via a caisson 5, into a rotary tubular furnace 6through which they circulated in counter-flow to hot gases with a verylow oxygen content. At the output from furnace 6, these gases passedthrough caisson 5 and exited therefrom at 7, while the excess granulatewas extracted by means of the lower hopper 8 of caisson 5 for recycling.

At the input to furnace 6, granulate 1 was subjected to a temperature of250° to 350° C. and, at its output, to a temperature of 700° to 750° C.The dwell time for the granulate in the furnace was approximately 30minutes.

The granulate left furnace 6 via a set of ports 9 and an output cone 10.It passed through a double air lock 11 cooled by a double jacket 12through which cooling air at 10° C. flowed at a rate of 350 m³ /hr(normal), this air being supplied by a fan 13.

The granulate was then introduced into an endless screw conveyor 14having a length of 5 m and a diameter of 18 cm, cooled by a doublejacket 15 having an annular space of 4 mm, through which water at 15° C.under a pressure of 5.5 bar circulated at a rate of 7.2 m³ /hr. Thegranulate was thus cooled by conduction to a temperature of 60° to 70°C. and was extracted at 16 from endless screw 14, at this temperature,at the rate of approximately 95 kg/hr. The water left the double jacketat approximately 18° C.

The gases used in furnace 6 arrived from the low outlet of a gasgenerator 17 (schematically represented upside down, for the purpose ofsimplification), the upper part of which was supplied with combustiongases of natural gas from a burner 18, partially cooled by mixing withthe recyled pyrolysis gases introduced into a recycled gas distributor19. The natural gas was injected into a burner 18, by means of aregulating valve 20, at a rate of 8 m³ /hr (normal) and the combustionair, of which there was a small excess, was injected into burner 18 bymeans of a fan 21, at a rate of 105 m³ /hr (normal). The recycledpyrolysis gases, at a temperature of 245° C., were injected intodistributor 19, by means of a fan 22, at a rate of 210 m³ /hr (normal).

The gases from generator 17 entered rotary furnace 6 at an adjustabletemperature in the region of 800° C. and exchanged their heat with thefurnace walls of refractory material and the granulates. The latter wereheated up to 750° C., while the gases cooled down.

The gases leaving furnace 6 via caisson 5 were laden with dusts or fineparticles produced by the erosion of the granulate in the furnace. Theywere conveyed, at 245° C. and at a flow rate of 326 m³ /hr (normal),into a cyclone filter 23. The filtered gases were either extracted fromthe installation by means of regulating valve 24, at 245° C. and at arate of 116 m³ /hr (normal) in order to be possibly reused, in themanufacture of the initial product, or recycled via regulating valve 25and fan 22 to gas generator 17.

This unit can function in automatic mode thanks to a set of threeregulating loops and a set of main and secondary safety devices.

The three regulating loops were essentially composed of the following.

1. Hot gas temperature regulation:

The gases from generator 17 must have a temperature that is as constantas possible, around a set-point fixed by the operator (850° C. in thecase of this example). The flow rate of recycled gases is thereforevaried according to the real temperature measured for the gases on theirentering furnace 6. This loop thus comprised:

a thermocouple for measuring the temperature of gases 26;

a proportional regulator, not shown, mounted in the control room; and

a valve 25 for regulating the flow rate of the recycled gases.

2. Regulation of the heat load of the rotary furnace:

The output temperature of the gases was measured, downstream of cyclonefilter 23 (245° C. in this example), and any deviation of themeasurement from the set-point fixed by the operator was corrected, byactuating the opening or closing of the electrovalves of natural gasburner 18. This loop thus comprised:

a temperature (250°-350° C.) measuring thermocouple 27;

a three-threshold regulator (dry contacts) 28; and

three electrovalves (not shown) mounted in parallel on the natural gascircuit of the burner.

3. Regulation for obtaining a depression in the hot gas generator:

For safety reasons, it is preferable to cause hot gas generator 17 tooperate at a slight depression. For this purpose, the pressure of thefirebox was measured, and the flow rate of the gases extracted from theunit was adjusted until values that were as close as possible to theset-points were obtained. This loop thus comprised:

a pressure sensor 29, mounted on generator 17;

a proportional regulator, not shown, mounted in the control room; and

a regulating shutter, or regulating valve, 24 for discharging the gases,with a pneumatic servo-motor, mounted on the gas discharge circuit.

The horizontal, direct heating type rotary furnace 6, used in thisexample, is shown in FIG. 2. It was composed of three sections, A, B andC, connected by flanges, and had an overall length of 6 m. It wasslightly inclined, towards the granulate output, for example at an angleα of approximately 2° in relation to the horizontal direction.

Section A of the product input, which was made of metal, wascylindro-conical. It was provided, in its cylindrical portion, with ahigh band 61 resting on four support rollers 62 driven by a motor forsubstantially horizontal rotation, not shown.

Section B, in which pyrolysis properly speaking was carried out, wasalso made of metal and was internally fitted with a refractory lining63, made, for example, of 11 cm "knife bricks" (fire bricks whichcontain 30-35% of Al₂ O₃ and have a density of 2).

Section C was also made of metal and was likewise internally fitted witha refractory lining 63. The said section C comprised a conical portionhaving ports 9 distributed at regular intervals over its circumferencefor discharging the pyrolized product, and a cylindrical portion foradmitting the pyrolysis gases, having a low band 64 resting on foursupport rollers 65.

The conical portion of section C was entirely surrounded by a annularlyshaped enclosure D, fixed in relation to the rotating assembly A, B, Cwhich formed the furnace, and was designed to receive the pyrolizedgranulate exiting via ports 9.

The seal between enclosure D and furnace 6 was provided by joints 66 and67. The lower portion of enclosure D communicated with double outputlock 11.

Example 2

Comparison between the porous, granular material obtained according toExample 1 and the starting product (granulate from the 1st, pyrolysis)

    ______________________________________                                                   GRANULATE FROM                                                                            GRANULATE FROM                                                    1ST PYROLYSIS                                                                             EXAMPLE 1                                              ______________________________________                                        Crushing strength                                                                          maximum 0.2 MPa                                                                             maximum 1 MPa                                      Impregnation (fixing of                                                                    2.5 to 3      3 to 4                                             phthalocyanine) (kg/m.sup.3                                                   of granulate)                                                                 Specific surface area                                                                      30 m.sup.2 /g 200 m.sup.2 /g                                     Microporous  0.05 to 0.25  0.25 to 1                                          volume (cm.sup.3 /g)                                                          Basicity*    5 to 6%       6 to 8%                                            ______________________________________                                         *Basicity is expressed as the percentage of residual potassium in the         product.                                                                 

It is to be noted that microporosity increases in a ratio of as much as1 to 5 when the granulate of the first pyrolysis is processed as inExample 1.

Example 3

Deodorization of water containing phenolic compounds

1st. test:

Water containing phenolic compounds has an unpleasant odor.

Treatment of this water by percolation through the porous, granularmaterial according to the invention reduced the concentration ofpollutant elements.

Water flow rate: 0.5 to 1 v/v/hr (volume/volume of material/hr).

                  TABLE 1                                                         ______________________________________                                                    BEFORE AFTER                                                      ______________________________________                                        C O D*        400 mg/l 80 mg/l                                                Phenols        24 mg/l 0 to 3 mg/l                                            ______________________________________                                         *C O D = Chemical oxygen demand.                                         

2nd. test

A mixture consisting of an evaporation condensate of wool scouring waterand noncondensable components from the evaporation of this same scouringwater, in the initial proportions of the scouring water, that is to say95/5 volume %, was treated as in the 1st. test.

Water flow rate: 0.2 to 0.5 v/v/hr.

                  TABLE 1b                                                        ______________________________________                                                    BEFORE AFTER                                                      ______________________________________                                        C O D         1000 mg/l                                                                              140 mg/l                                               Phenols        14 mg/l nil                                                    ______________________________________                                    

Example 4

Deodorization of evaporation condensates of the wool scouring waters

It is of interest to deodorize the evaporation condensates of woolwashing in order to reuse them for wool washing or scouring.

The product obtained in Example 1 was washed with water, at 70° C., toextract the soluble salts therefrom.

1st. test

Two columns were used in succession, each column containing 150 cm³ ofwater washed and dried product. The condensed water was diffused throughthe support, at a rate of 0.47 m/hr, in an ascending stream. The flowrate was 0.5 v/v/hr, i.e. 150 cm³ /hr.

The daily volume thus deodorized was 3.6 liters.

2nd. test

In this test, water was passed in succession through three columns, eachcolumn containing 500 cm³ of the product obtained according to Example1, water washed and dried. The speed of passage was 0.14 m/hr in anascending stream. The flow rate was 0.2 v/v/hr, i.e. 300 cm³ /hr.

The daily volume thus deodorized was 7.2 liters.

At the end of the cycle, the support was reactivated thermally in thefurnace between 600° and 650° C., for 3 hours, with protection from air.

Example 5

1st. test:

Procedure was as for Example 4, 2nd. test.

18 liters of evaporation condensates were diffused through the productof Example 1, treated as described in Example 4, prior to saturation ofthe product. The product or support was considered to be saturated when,in the columns, it no longer fixed more than 50% of the initial chemicaloxygen demand (COD) of the non-treated water.

In addition, the phenol concentration was quantitatively assessed using4-amino-antipyrine which, upon condensing with the phenols, develops acoloring.

The results obtained are grouped together in Table 2.

                  TABLE 2                                                         ______________________________________                                        DEODORIZED  CONDENSATE                                                        CONDENSATE  VOL.: SUPPORT COD     PHENOLS                                     VOLUME* (1) VOL. RATIO    (mg/l)  (ppm)                                       ______________________________________                                        0           --            400     24                                          2.1          7            15      0                                           5.1         17            20      0                                           10          33            20      0                                           15          50            80      3                                           18          60            180     16                                          ______________________________________                                         *The measurements were carried out during the cycle, after deodorization      of 2.1 1, 5.1 1, etc.                                                    

2nd. test

Procedure was as for the 1st. test hereabove.

                  TABLE 2b                                                        ______________________________________                                        DEODORIZED  CONDENSATE                                                        CONDENSATE  VOL.: SUPPORT COD     PHENOLS                                     VOLUME* (1) VOL. RATIO    (mg/l)  (ppm)                                       ______________________________________                                        0           --            1000    14                                           7.2         4.8          80      0                                           14.4         9.6          100     0                                           21.6        14.4          120     0                                           28.8        19.2          140     0                                           36.0        24.0          150     0                                           43.2        30.8          190     0                                           50.4        33.6          200     0                                           ______________________________________                                         *Same comment as for Table 2.                                            

Thermal regeneration in an inert medium enabled the support to be reusedin treating condensates by percolation, this holding good as long asthermal reactivation was possible.

Example 6

Deodorization of steam distillation (stripping) condensates

Procedure was as in Example 4, 1st. test, and Example 5, 2nd. test.

The results obtained are grouped together in Table 3.

                  TABLE 3                                                         ______________________________________                                        DEODORIZED  CONDENSATE                                                        CONDENSATE  VOL.: SUPPORT COD     PHENOLS                                     VOLUME* (1) VOL. RATIO    (mg/l)  (ppm)                                       ______________________________________                                        0           --            140     16                                          2.1          7            6       0                                           5.1         17            7       0                                           10          33            10      0                                           15          55            32      5                                           18          60            70      7                                           ______________________________________                                         *Same comment as for Table 2.                                            

Example 7

Neutralization of acidity in fats

Porous, granular material according to the invention, obtained from asecond pyrolysis at a maximum temperature of 750° C. for 50 minutes, wascalcined in an oxidizing atmosphere at 400° C., for 8 hours, to increaseits surface basicity.

With the porous, granular material thus treated, it proved possible to,concommittantly, neutralize fatty acids and to accelerate thedecomposition of the peroxides.

Suintine was placed in a hydro-alcoholic solution to which 130 volumeshydrogen peroxide had been added. The solution was then diffused in anascending stream through the granular material treated as describedabove, at a flow rate of 0.1 v/v/hr.

Before and after the treatment, the free acidity, the peroxide numberand the Lovibond color of the suintine were measured.

The free acidity measurement carried out consisted in expressing theacidity as the percentage of oleic acid present in the substance to beanalyzed. This is a way of expressing the acid number.

The peroxide number was given by the number, expressed inmilliequivalents, of active oxygen contained in 1000 g of substance.

Measurement of the Lovibond color is a measurement of the color of anoil or a melted fat. It is a comparative measurement which is carriedout on a Lovibond comparator as follows. Melted suintine was placed inan 0.635 cm (1/4 inch) cell. The cell was placed in the comparator andcolored plates (red, blue and green) or filters were associatedtherewith in order to obtain the same color as that of the suintine.When this result was obtained, the color was expressed by the numbers ofthe filters used (for example yellow 20).

In the present case, only the value or number of the yellow filter wasused.

The results are expressed as follows: Lovibond color, 1/4 inch cell,yellow=for example, 20.

The results of these 3 measurements are grouped together in Table 5thereafter.

                  TABLE 5                                                         ______________________________________                                        Free acidity      Peroxide Lovibond color                                     (%)               number   (yellow)                                           ______________________________________                                        Before  4             90 to 12 >80                                            After   0.2           40 to 8  20                                             ______________________________________                                    

Example 8

Sweetening of a petroleum cut including sulfur-containing compounds

A petroleum cut (boiling point 135° to 250° C.) including 120 ppm ofsulfur-containing compounds (mercaptans) was sweetened using, on onehand, the granular material of the first pyrolysis which absorbed littlecatalyst (approximately 2.5 kg/cm³ of cobalt phthalocyanine) and, on theother hand, the granular material according to the invention obtained bypyrolysis for approximately 1 hour at a maximum temperature of 700° C.,which absorbed far more catalyst (approximately 4.7 kg/cm³ of cobaltphthalocyanine).

It was found that, for the same results (mercaptan content of theeffluents between 5 and 10 ppm), the volume of petroleum cut treated perhour was doubled with the granulate according to the invention, inparticularly due to an increase in the quantity of catalyst that couldfixed on this granulate.

I claim:
 1. A porous, granular material comprising carbon, and silicon,oxygen, sodium, potassium, magnesium, calcium, aluminum and ironcombined at least partially in the form of silica, of water-solubleSilicate mineral salts and of water-insoluble aluminosilicate mineralsalts, said mineral salts being present in a mineral matrix which, inthe presence of water, has the properties of a base, which granularmaterial does not disintegrate in the presence of water and has:(a) aparticle size in the range of from approximately 1 to 5 mm; (b) acrushing strength, or mechanical strength, in the range of from 0.75 to1 MPa; (c) a density of between 0.7 and 0.8 g/cm³ ; (d) a BET specificsurface area of between 100 and 200 m² /g; (e) a microporous volume ofbetween 0.25 and 1 cm³ /g; and (f) a carbon content in the range of from8 to 11 weight %, the balance being essentially made up by said mineralmatrix, which comprises a crystalline phase of said insolublealuminosilicates.
 2. The porous, granular material according to claim 1,wherein the particle size is in the range of from 1 to 3 mm.
 3. Theporous, granular material according to claim 2, wherein the particlesize is in the range of from 1 to 2 mm.
 4. The porous, granular materialaccording to claim 1, wherein:the particle size is in the range of from1 to 3 mm; the crushing strength, or mechanical strength, is between0.75 and 0.95 MPa; the BET specific surface area is between 160 and 200m² /g; and wherein the porous, granular material has a pH value,measured for the washing waters, of over
 11. 5. The porous, granularmaterial according to claim 1, wherein the porous granular material hasa silica content on the order of 45 weight %.
 6. The process for themanufacture of the porous, granular material according to claim 1, whichcomprises the steps of:(a) obtaining an essentially mineral material byconcentrating wool scouring waters to obtain a dry matter content ofapproximately 70% and pyrolizing the resulting concentrate at atemperature of between 400° and 600° C., with protection from air andcooling; (b) subjecting the essentially mineral material to grinding,compacting, granulating and screening operations to obtain a granulatehaving a particle size ranging from approximately 1 to 5 mm; (c)subjecting the granulate obtained in step (b), to a second pyrolysis, ina non-oxidizing atmosphere, at a temperature which is graduallyincreased from a value in the range of from 250° to 350° C. to a valuein the range of from 700° to 950° C., for a total duration of 15 to 60minutes; and (d) cooling the granulate thus obtained, with protectionfrom air, and under conditions such that it is not subjected to thermalshock.
 7. The process according to claim 6, wherein at the time ofcompacting, petroleum pitch or coal tar pitch, in a proportion of 5 to10 weight % in relation to the weight of the material obtained followinggrinding, and/or sludges containing metals or metal salts, are added. 8.The process according to claim 6, wherein the second pyrolysis iscarried out in a rotary furnace fitted with refractory walls.
 9. Theprocess according to claim 6, wherein the atmosphere in the furnace is areducing atmosphere.
 10. The process according to claim 6, wherein thegranulate is cooled in fine sand or in a tube having a double jacketthrough which cold water circulates.
 11. The process according to claim6, wherein the second pyrolysis is carried out at a temperature which isgradually increased from a value in the range of from 250° to 350° C. toa value in the range of from 700° to 750° C.
 12. The process for themanufacture of the porous, granular material according to claim 1, whichcomprises the steps of:(a) obtaining an essentially mineral materialhaving a particle size in the range of from about 1 to 5 mm, byconcentrating wool scouring waters to obtain a dry matter content ofapproximately 70% and pyrolizing the resulting concentrate at atemperature of between 400° and 600° C., with protection from air andcooling; (b) subjecting the essentially mineral material to a secondpyrolysis, in a non-oxidizing atmosphere, at a temperature which isgradually increased from a value in the range of from 250° to 350° C. toa value in the range of from 700° to 950° C., for a total duration of 15to 60 minutes; and (c) cooling the granulate thus obtained, withprotection from air, and under conditions such that it is not subjectedto thermal shock.
 13. The process according to claim 12, wherein thesecond pyrolysis is carried out in a rotary furnace fitted withrefractory walls.
 14. The process according to claim 12, wherein theatmosphere in the furnace is a reducing atmosphere.
 15. The processaccording to claim 12, wherein the granulate is cooled in fine sand orin a tube having a double jacket through which cold water circulates.16. The process according to claim 12, wherein the second pyrolysis iscarried out at a temperature which is gradually increased from a valuein the range of from 250° to 350° C. to a value in the range of from700° to 750° C.
 17. A method of purifying liquids, comprising contactinga liquid to be purified with the porous, granular material according toclaim
 1. 18. A method of catalyzing an oxidation reaction, comprisingcontacting gas reactants with the porous, granular material according toclaim
 1. 19. A method of forming a catalyst support, comprisingimpregnating the porous, granular material according to claim 1 with acatalyst.
 20. A method of forming a composite catalyst useable inpetrochemistry, comprising impregnating the porous, granular materialaccording to claim 4 with a metallic chelate.